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X-400 Web Enabled I/O Controller | ControlByWeb
5 Year Warranty

Modular, web-enabled, industrial I/O controller that allows you to add various combinations of I/O to tailor it to your specific application. Expansion modules can either be directly connected to the X-400 through the expansion bus, or you can connect remote ControlByWeb devices through an Ethernet network, including the Internet.


Relays: Up to 64 I/O

Current: See expansion module specifications


Analog: Up to 64 I/O

Digital: Up to 64 I/O

Current: See expansion module specifications





In Stock


Expandable & Full-Featured

Expansion Modules
Add up to 32 expansion modules and/or remote I/O devices for remote monitoring and control for up to 64 I/O.

Custom Logic
Create custom logic with no scripting necessary using the X-400’s intuitive Task Builder.

Ethernet Control & Monitoring
Control and/or monitor over any TCP/IP network including LAN and WAN networks, IP-based industrial control networks, and the Internet.

Cellular Control & Monitoring
The X-400C model includes a cellular modem for remote communication and can also act as a network connectivity failover. See coverage map.

X-400 web enabled controller connected to multiple expansion modules via an expansion cable

Unlimited Possibilities! Control up to 64 I/O

Expandable I/O Solutions

Expansion Bus

Add I/O expansion modules (below) to the X-400 for an I/O solution that is tailored to your specific application. These modules provide a broad mix of capabilities that are ideal in a variety of industries and applications from data acquisition to complex process control.

Learn More About Expandable I/O Options

Peer-to-Peer Communication (P2P)

The X-400 supports peer-to-peer communication between ControlByWeb devices. The X-400 can communicate with all expansion modules and other ControlByWeb devices but offers instantaneous messaging between 400 Series products. This means that the X-400 controller can monitor and control I/O on other 400 Series products as if it was directly connected to the controller!

Peer to Peer Communication

Monitoring & Control | Local & Remote


The X-400 connects to IP networks and control systems using TCP/IP communication over Ethernet. This is ideal for local monitoring and can also be used for remote monitoring by visiting the device IP address on the Internet through port forwarding. Port forwarding also allows peer-to-peer communication between devices.


Remote locations without an Internet connection are now easier to monitor with the cell-enabled X-400C model. Our cellular data plans include a ControlByWeb Cloud subscription to streamline access to the device setup, task builder, and control pages. The cellular model connects to the strongest available network. Check coverage map.


The ControlByWeb Cloud simplifies monitoring, control, and data logging. It provides access to your controller, but keeps logic on the device so you are not dependent on network connectivity. Get the best of both worlds with our reliable platform. A cloud subscription is included with your X-400C cellular data plan at no additional cost.

Smart Dual-SIM Technology

The X-400C uses intelligent Dual-SIM technology to connect to the best network available. It will automatically switch between networks as needed to maintain the strongest possible connection. This improves connectivity and makes connecting in tough locations more reliable.

Cloud Gateway Device

The X-400 is compatible with the ControlByWeb cloud and acts as a master device to other ControlByWeb devices. If you have an incompatible device and need to connect to the cloud, the X-400 makes it possible. Speak to a sales representative to learn more about how we can get you connected.

Custom Control/Logic

Task Builder

The X-400's built-in interface allows you to create custom "Tasks" for simple and advanced control logic.

Easily create tasks based on inputs or outputs’ status. Create up to three actions for each task providing you with the ultimate control and monitoring solution for your application!

Create up to 50 Scheduled Tasks, 50 Conditional Tasks, 20 Automatic Reboot Tasks, and 20 Override Schedules.

The X-400 also has a built-in BASIC interpreter for more advanced or custom applications.

X-400 Add Conditional Task

Conditional Tasks

Conditional tasks are triggered depending on an input's or output's status.

Conditional tasks are commonly used for creating email/text alerts, controlling outputs, and logging.

Scheduled Tasks

Scheduled tasks perform actions at preset times on specific days.

Scheduled tasks are commonly used to control relays or log I/O data at a specified time.

Advanced Logic

Write BASIC scripts for more advanced logic. The X-400 also includes powerful features such as, automatically rebooting devices when they become unresponsive (i.e., cameras, routers, servers, etc.).

Advanced Features


The X-400 offers the ability to log a variety of data points such as local and remote I/O, registers, and voltage. Log entries can be made at preset intervals, scheduled times, triggered by I/O changes or logic events.

Schedule a daily log file to be sent via email or uploaded via FTP server.


Graph the current log file and view the I/O's status over time.

X-400 Graphs I/O states over time, or by event


The X-400 supports HTTPS connections, can send encrypted emails, can communicate with remote devices using TLS.

Other Advanced Features

The X-400 has more advanced features such as the ability to initiate a connection to remote servers, BASIC programming, admin/manager/user permissions, etc.

Control Page

Users access the X-400 through a built-in web page, called the Control Page. The Control Page can be customized by administrators.

Use the Control Page to:

  • Control (On, Off, or Pulse):
    • Digital Outputs
    • Relays
  • Monitor status of:
    • Digital Inputs
    • Analog inputs
    • 1-Wire sensors
    • Timers
    • Registers

Optionally, the Control Page can be password protected for additional security.

X-400 Monitoring and Control Page

I/O such as relays, digital/analog inputs need to be added to the X-400 via expansion or remote I/O modules before they can appear on the Control Page.

User Permissions

The X-400 supports three types of users that provide different levels of access to the module's settings and Control pages. Each user type has a unique password and is configured by the administrator in the setup pages.


Administrators have full access to all device settings, tasks, and the Control Page.


Managers only have access to Scheduled Tasks and Control Page.


Access to Control Page only. Administrators have the option to enable/disable this password.

All of these features make the X-400 the ultimate solution for monitoring and data acquisition!

ControlByWeb Cloud

Our ControlByWeb Cloud makes accessing your data simple and secure without any of the drawbacks of cloud dependency. It provides access to our cellular devices and works with any 400 Series devices (X-400, X-405, X-410, etc.) and Wi-Fi modules (see compatible devices).

The cloud is included at no additional cost with a X-400C cellular data plan and provides remote access and enhances setup and commissioning.

With the cloud you can manage multiple locations and many devices with a single login, create parent-child account hierarchy that makes data organization easy, and log data in the cloud for easier access and easy download.

Here’s what the ControlByWeb Cloud does for you:

  • Easier Access
  • Single Password Authentication
  • Data Logging
  • Parent-Child Hierarchy
  • Logic Stays on the Device, Not the Cloud
  • Connect Unlimited Endpoints
  • Layered Security
  • Connect Incompatible Devices

Learn more about the ControlByWeb Cloud and how it can help you monitor and control your assets and processes much easier.

Applications - Industrial Internet of Things (IIoT)

The X-400 is a simple, but powerful Ethernet I/O module for large and small IIoT applications which require simple or advanced control logic.

The X-400 is ideal for applications where sensors and electrical devices are spread out and connected to various 400 Series devices. Here are a couple of IIoT examples for the X-400:

Sports Web-Based Lighting Controller with Scheduling

The following illustration shows two X-400 devices used for controlling a series of lights using its built-in web pages. The X-400's built-in features make it easily configurable as a robust light controller.

Location 1: X-400 - Light Controller

The X-400 connects to several X-11s expansion modules, and with the X-11s' high-current relays, it allows you to directly wire as many lights as needed without needing to use an interposer relay!

The X-400 can be conveniently located wherever the lights are wired.

Seamless Communication

The X-400 devices can seamlessly communicate with one another via peer-to-peer communication. This allows the push buttons connected to one X-400, to control the lights connected to the other X-400.

Location 2: X-400 - Push-Button Controller

Another X-400 device is able to be conveniently wired to all of the push-button switches which control the lights.

Configure the X-400 to make a push-button:

  • Set the lights on a timer.
  • Turn on an individual light or group of lights.
  • Stagger the order lights turn on to reduce the current draw.
  • Schedule the lights to turn on/off at preset times and days
X-400 Remote Web-Enabled Light Controller

The image above is for illustration purposes only. It does not represent actual wiring.

Other IIoT Applications

Door and motion sensor

Security Automation

Control different combinations of locks, sensors, lights, etc. using the X-400 module.

Server Room

Server Room Monitoring & Auto Reboot

Monitor a server room environment. Automatically reboot unresponsive network devices.


  • Expansion Bus - Control, monitor, and log 32 expansion and/or remote modules, or up to 64 I/O
  • Secure Peer-to-Peer (P2P) Communication
  • 1-Wire Bus: Monitor up to 16 temp/humidity sensors: -67°F to 257°F (-55°C to +125°C)
  • Secure, built-in web server for configuration and remote monitoring
  • User Permissions: Admin, Manager, User
  • Task Builder
    • 50 Scheduled Tasks
    • 50 Conditional Tasks
    • 20 Reboot Tasks
    • 20 Override Schedules
  • Send email alerts based on user-defined conditions (supports encrypted email servers, such as Gmail)
  • Real-Time Clock with NTP server synchronization
  • Automatic daylight savings and leap year adjustment
  • Highly configurable - Almost any combination of input/relay control possible
  • No software required
  • Customizable, web-based Control Page
  • BASIC script support for advanced flexibility
  • Data Logging
  • Graphing (logged data)
  • HTTPS/TLS encrypted
  • Static or DHCP IP address configuration
  • Modbus, SNMP, Remote Service, IP Filtering
  • Field updatable
  • Removable 14-Terminal connector for easy installation
  • Rugged DIN-Rail/wall-mountable enclosure
CE listed RoHS compliant Made in the USA

Frequently Asked Questions


The X-400 and X-400C share all the same features and functionality except the cellular modem. The X-400C adds the cellular modem for remote access where Internet access isn't available, or for Internet failover to maintain connectivity.


The X-400C works with ControlByWeb cellular data plans only, which include a device seat on our cloud. This makes the experience as easy as possible and ensures the most reliable connection.


We offer a 5 MB/mo, 10 MB/mo, and 30 MB/mo plans. We recommend the 5 MB/mo plan for those who are using the X-400C as an Internet failover device. This plan is perfect for occasional use and saves you money you don't need to spend. Our 10 MB/mo plan is ideal for monitoring and data logging with a few devices in remote locations. The 30 MB/mo plan is great for monitoring and logging with more devices, or for applications that require frequent remote access to device control and setup pages.


You'll activate failover mode in the device set up inside the Cellular menu, under General Settings. Use the Mode dropdown menu to select "Use Cellular as Backup (When wired network fails)". By default it will ping our cloud over the Ethernet port and if it fails, the device will automatically switch to cell mode. When the Ethernet reconnects, it will automatically resume Ethernet mode.


We bill for data plan overages monthly. We've kept the cost minimal at only $0.50 per MB no matter which plan you have. While for frequent data overages you will want to upgrade your plan, occasional overages won't dramatically increase your cost.


You'll start by creating your cloud account and adding the X-400C as a device in the cloud interface. If you bought your device and data plan together, your device will come pre-programmed and you'll only need to activate the SIM card. If you bought them separately, you'll receive a data plan code via email and you'll be prompted to enter that code during the setup process prior to SIM activation. Once the SIM is activated, you'll power on (or power cycle) your X-400C device. It will automatically connect to the cloud after a few minutes.


We are working on International cell coverage and data plans. For more information, please contact us.


In the X-400 device setup, click on the "Devices" tab and then on the "Add Device +" button in the bottom right-hand corner. There you can add other ControlByWeb devices. Once finished, you'll need to add the I/O in the I/O Setup tab. Next, you can create any logic on the X-400 device by clicking on the "Control/Logic" tab. Finally, you can pass remote device data to the cloud for logging if you want on the "Logging" tab.

X-400 Part Numbers

X-400-I 1-Wire Bus: Up to 16 sensors
Expansion Bus - Up to 32 Expansion Modules
9-28 VDC
X-400C-I-CA Cellular Module: see coverage map.
1-Wire Bus: Up to 16 sensors | Expansion Bus - Up to 32 Expansion Modules
9-28 VDC

More Information:


Where to Buy

Click "Buy Online" to view part numbers and pricing. X-400 is available in the USA and internationally, and can be purchased either from us or an Authorized Distributor.

Expansion Modules

X-11s™ | Dual, High-Current Relay Expansion Module

Part number(s): X-11s (Requires an X-400 or X-600M controller)


  • 2 large SPDT (Form C) relays (277 VAC (general purpose) 110VDC (NO contact, resistive) 30 VDC (NC contact, resistive) and 20A)
  • Removable locking connector supports 24AWG to 10AWG
  • Two relay LEDs
  • Powered through expansion bus

X-12s™ | Eight-Relay Expansion Module

Part number(s): X-12s (Requires an X-400 or X-600M controller)


  • 8 SPST (Form A) relays with shared common connection (2 commons)
  • Removable terminal connector
  • Eight relay LEDs
  • Powered through expansion bus

X-13s™ | Thermocouple Expansion Module

Part number(s): X-13s-K (Requires an X-400 or X-600M controller)


  • Supports one or two type K thermocouples
  • Fault LED for each thermocouple
  • Powered through expansion bus

X-15s™ | Eight Digital Input Expansion Module

Part number(s): X-15s (Requires an X-400 or X-600M controller)


  • 8, Optically-Isolated inputs with shared common for each input
  • Indicator LED for each input
  • Automatic de-bounce
  • Interrupt output to Master (X-600M) for fast response
  • Built-in timers, counters, for each input
  • Removable terminal connector
  • Powered through expansion bus

X-16s™ | Eight Analog Input Expansion Module

Part number(s): X-16s (Requires an X-400 or X-600M controller)


  • 8, 0-5V precision analog inputs
  • 24-bit A/D converter
  • Single or differential input measurements
  • 5.0V reference output
  • Removable terminal connector
  • Powered through expansion bus

X-17s™ | 4 Relay, 4 Input Expansion Module

Part number(s): X-17s (Requires an X-400 or X-600M controller)


  • 4 SPST (Form A) relays
  • 4 Optically-Isolated digital inputs (common negative)
  • Removable terminal connector
  • Powered through expansion bus

X-18s™ | 10 High-Current Relay Expansion Module

Part number(s): X-18s (Requires an X-400 or X-600M controller)


  • 10 Large SPDT (Form C) relays (15A, 277VAC, 30VDC)
  • 1/4 inch tab connectors
  • 11 LEDs for relays and power
  • Powered externally

X-19s™ | 16 Relay, 16 Digital and 4 Analog Input Expansion Module

Part number(s): X-19s (Requires an X-400 or X-600M controller)


  • 16 SPST relays
  • 16 Optically-Isolated digital inputs
  • 4 Single-ended channels analog inputs
  • 33 LEDs for relays, digital inputs, and power
  • Powered externally

X-20s™ | 6 Relay, 6 Digital Input Expansion Module

Part number(s): X-20s (Requires an X-400 or X-600M controller)


  • 6 SPDT (Form C) relays
  • 6 Optically-Isolated digital inputs
  • 13 LEDs for relays, digital inputs, and power
  • Powered externally

X-21s™ | Four Relay Form C / SPDT Expansion Module

Part number(s): X-21s (Requires an X-400 or X-600M controller)


  • 4 Form C / SPDT (Form C) relays
  • Removable terminal connector
  • LED Indicators for relays and power
  • Powered through expansion bus

X-22s™ | Eight Analog Input Expansion Module

Part number(s): X-22s (Requires an X-400 or X-600M controller)


  • 8 precision analog inputs
  • Configurable voltage ranges: ±1V to ±10V
  • Connect 4-20mA sensors. No external resistors required.
  • High input impedance facilitates external resistors for voltage scaling, if required.
  • Powered through expansion bus

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Warning: May contain chemicals, including Nickel (metallic), known to the State of California to cause cancer and reproductive harm. -



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